1. Field of the Invention
The present invention relates to a golf club head. In particular, the present invention relates to a golf club head having a CFRP member.
2. Description of the Related Art
In a golf club head, a coefficient of restitution and a volume of the head are regulated by the rule. In respect of a swing balance, a weight of the head is restricted. Furthermore, in respect of practicality, high strength is required. The regulation and the restriction complicate the design of a head having enhanced performance.
In order to improve the performance of the head, a head using CFRP is known. The CFRP means carbon fiber reinforced plastic. The CFRP can have specific strength higher than that of titanium. An excess weight can be created by using the CFRP. A position of a center of gravity of the head can be changed by redisposing the excess weight. The excess weight can improve a degree of freedom of the design of the head.
Japanese Patent Application Publication No. 4222118 (US2005/0026721) discloses a hollow golf club head having a front face body made of an integral titanium-based metal material, a metal sole plate, and a fiber-reinforced resin body. Paragraph [0036] discloses a sheet having a carbon fiber obliquely oriented by 60 degrees in a clockwise direction to a toe-heel direction, and a sheet having a carbon fiber obliquely oriented by 60 degrees in a counterclockwise direction to the toe-heel direction. In FIG. 6 of Japanese Patent Application Laid-Open No. 2005-253606, a laminate oriented in four directions is disclosed. Japanese Patent Application Laid-Open No. 2005-312646 (US2005/0245328, US2009/0139643, US2009/0176600) discloses a constitution in which fibers are crossed at the angle of 30 to 90 degrees. Japanese Patent Application Laid-Open No. 2005-296626 (US2005/0209022) discloses a resin member including a 0° direction prepreg of which a fiber substantially makes an angle of 0 degree to a front-back direction line of a head, and a 90° direction prepreg of which a fiber substantially makes 90 degrees to the front-back direction line of the head.